Abstract
We compared estimates of stream habitat at the watershed scale using the basinwide visual estimation technique (BVET) and the representative reach extrapolation technique (RRET) in three small watersheds in the Appalachian Mountains. Within each watershed, all habitat units were sampled by the BVET, in contrast, three or four 100-m reaches were sampled with the RRET. The number of pools was higher and the number of cascades was lower when estimated by the RRET than they were when estimated by the BVET, whereas the average areas of all habitat types estimated by the RRET were smaller. At the watershed scale. eight out of nine estimates of total habitat area by habitat type derived from the RRET were outside the 95% confidence intervals derived from the BVET. Depth estimates were consistently smaller with the RRET than with the BVET. Large woody debris estimates with the RRET were less than with the BVET in two of three watersheds and were greater in one watershed. We observed that the degree to which habitat in a RRET assessment reflects conditions at a larger scale depends on the selection of representative reaches. Habitat estimates based on the BVET were a more accurate reflection of conditions existing in the three small southern Appalachian watersheds than estimates derived from the RRET. The BVET permitted greater amounts of habitat to be surveyed with known accuracy and precision.
Citation
Dolloff, C. Andrew; Jennings, Holly E. 1997. A Comparison of Basinwide and Representative Reach Habitat Survey Techniques in Three Southern Appalachian Watersheds. North American Journal of Fisheries Management 17.339-347, 1997
